1. Field
One or more exemplary embodiments relate to a thermoelectric device and a method of manufacturing the same.
2. Description of the Related Art
Thermoelectric conversion refers to energy conversion between thermal energy and electrical energy. Electricity is generated when a temperature difference exists between two ends of a thermoelectric material, which is referred to as the Seebeck effect. Further, a temperature gradient is generated between the two ends of the thermoelectric material when an electrical current flows in the thermoelectric material, which is referred to as the Peltier effect.
Heat generated from a computer, an engine of a car, or other devices or structures, may be converted into electrical energy using the Seebeck effect and various cooling systems using no refrigerant may be realized using the Peltier effect. As interest in new forms of energy development, wasted energy recycling, and environmental protection, has increased in recent times, interest in thermoelectric devices has also particularly increased.
The efficiency of a thermoelectric device is determined by a performance coefficient of a thermoelectric material, also referred to as a figure of merit (“ZT”) coefficient. The ZT coefficient, which is non-dimensional, may be represented by Equation 1.
                    ZT        =                                                            S                2                            ⁢              σ                        k                    ⁢          T                                    (                  Equation          ⁢                                          ⁢          1                )            
In Equation 1, the ZT coefficient is proportional to a Seebeck coefficient S and electrical conductivity σ of thermoelectric material and is inversely proportional to thermal conductivity k of thermoelectric material. Here, the Seebeck coefficient S represents the magnitude of a voltage generated according to variations in unit temperature (“dV/dT”).
However, the Seebeck coefficient S, the electrical conductivity σ, and the thermal conductivity k are not independent parameters and thus a thermoelectric device having a high ZT coefficient, indicating a high efficiency, may not be easily realized.